I think the squad Conte took over was worse than Manchester United's squad. However, their additions in January have made a massive difference. Their attack was lopsided, with no effective right winger. Their midfield had no depth, and the first-team had zero creativity before those transfers.
Tottenham's attack is undoubtedly better, though. Not sure any Premier League club has a better first-team attack than Tottenham in the league, especially since the addition of Kulusevski. They have the best striker in the league and, arguably, the best left-winger with Son (that one is a bit more disputable). It is easily a match for Liverpool and Manchester City.
However, their midfield was pretty poor. Bentancur has made a massive difference, but the midfield that Conte took over was worse than what Manchester United. It had absolutely nothing to it: no creativity and was completely flat.
Defence. It is dodgy still. They still concede a lot of sloppy goals. This is a place where they definitely need signings, but they have improved a bit under Conte.